Add security section to issue template (#9467)

Author: mikaelm12

.github/ISSUE_TEMPLATE/bug_report.md

@@ -3,6 +3,8 @@ name: Bug report
 about: Create a report about something that is not working
 ---
 
+### If you believe you have an issue that affects the security of the platform please do NOT create an issue and instead email your issue details to [email protected]. Your report may be eligible for our [bug bounty](https://technet.microsoft.com/en-us/mt764065.aspx) but ONLY if it is reported through email.
+
 ### Describe the bug
 A clear and concise description of what the bug is.